Surgical Tack and Tack Drive Apparatus

ABSTRACT

A fastener is provided for attaching body tissue to body tissue or another material to body tissue. The fastener includes a head portion, a body portion, and an anchoring element. The anchoring element is on the distal end of the fastener, and has one or more barbs or similar anchoring devices that are configured to prevent removal of the fastener once it is attached to the body tissue. The head is located on the proximal end of the fastener, and anchors the body tissue or other material when the fastener is attached to the body tissue. The disclosure also provides a driver apparatus for inserting the fasteners. The applicator device includes an indexer for sequentially indexing one or more fasteners, and a driver for applying an insertion force to a fastener that is sufficient to insert the fastener and attach it to body tissue. The disclosure also provides a method of using the fastener and applicator device.

FIELD OF THE INVENTION

The present invention relates generally to surgical fasteners and driveapparatus for use with surgical fasteners. More specifically, thepresent invention relates to soft tissue surgical tacks and a tack drivesystem for the fixation of hernia mesh.

DESCRIPTION OF RELATED ART

Fasteners are used in various surgical procedures to secure tissue andobjects to tissue. One such surgical procedure is the repair of ahernia. A common solution in hernia repair is to attach a mesh patchover the defect so that bowel and other abdominal tissue are blockedfrom forming an external bulge that is typical of abdominal hernias.

At present, there are a variety of devices and fasteners available toattach the mesh patch to the inguinal floor or abdominal wall. Suchdevices and fasteners include sutures, surgical staples, and tacks. Therole of the devices and fasteners is to keep the mesh in proper positionuntil tissue in-growth is adequate to hold the mesh in place undervarious internal and external conditions.

A hernia repair surgery can be performed either through the traditionalopen procedure or through the current trend of less invasive proceduressuch as laparoscopic procedures. Certain previously used devices andfasteners are better suited for open procedures while other devices andfasteners are better suited for laparoscopic procedures.

SUMMARY

In view of the foregoing, there exists a need for a hernia mesh fastenerthat is simple to deploy, securely fastens to bodily tissue, and can beabsorbed by the body after a period of time when the tissue in-growth tothe mesh obviates the need for a fastener. A need also exists for asimple inexpensive fastener drive apparatus that is easy to handle anduse by a surgeon and is adaptable for use in both open and laparoscopicprocedures. Accordingly, various embodiments disclosed herein provide afastener, a drive apparatus, and a method for using the drive apparatusto apply a fastener

It is therefore a feature of an embodiment to provide a fastener forattaching to a body tissue, having a longitudinal direction, a proximalend, and a distal end. The fastener comprises a head portion disposednear the proximal end of the fastener and having a proximal surface, adistal surface, and a passage that extends through the head portion fromthe proximal surface to the distal surface. The fastener furthercomprises a body portion extending from the distal surface of the headportion in the longitudinal direction. The fastener further comprises ananchoring element extending from the body portion, and including atleast one barb that is at least partially disposed adjacent the distalend of the fastener.

It is another feature of an embodiment to provide an applicator forapplying a barbed fastener to a body tissue, the applicator comprisingan elongated tubular portion having a longitudinal axis extending from aproximal end to a distal end and having a tube interior accessible byproximal and distal tube openings. The tube interior is sized andconfigured for receiving the barbed fastener. The applicator furthercomprises an indexer disposed at least partially inside the tubeinterior. The indexer has an elongated indexer body member and afastener engaging portion adapted to engage the barbed fastener and movethe barbed fastener from an initial fastener position in the tubeinterior to a firing position as the indexer moves from a firstlongitudinal position to a second, more distal longitudinal position.The applicator also comprises a driver disposed at least partiallyinside the tube interior. The driver has a driver engaging portion atits distal end. The driver engaging portion is adapted to engage thebarbed fastener in the firing position and selectively apply an ejectionforce to the barbed fastener, thereby ejecting the barbed fastener fromthe tube interior through the distal opening.

It is another feature of an embodiment to provide a method a method ofapplying a fastener to a pre-determined target insertion point on a bodytissue. The method comprises providing a fastener having a head portionhaving a passage formed therethrough, an anchoring element configuredfor engaging the body tissue, and a body portion extending distally fromthe head portion to connect the anchoring element thereto. The methodfurther comprises providing a fastener applicator comprising anelongated tubular portion having a longitudinal axis extending from aproximal end to a distal end and having a tube interior accessible byproximal and distal tube openings, an indexer disposed at leastpartially inside the tube interior, the indexer being adapted toselectively move the fastener from an initial position to a firingposition adjacent the distal tube opening, and a driver disposed atleast partially inside the tube interior, the driver being adapted toengage the fastener in the firing position and selectively apply anejection force to the fastener. The method still further comprisesplacing the fastener in the initial position within the tube interiorand causing the indexer to selectively move the fastener from theinitial position to the firing position. The method also comprisespositioning the distal opening of the tube assembly adjacent the targetinsertion point and causing the driver to apply the ejection force tothe fastener, thereby ejecting the fastener through the distal openingand into the body tissue at the target insertion point.

These and other objects, features, and advantages of the presentinvention will appear more fully from the following description of theexemplary embodiments, taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a fastener in accordance with anexemplary embodiment;

FIG. 2 is a top view of a fastener in accordance with an exemplaryembodiment;

FIG. 3 is a front view of a fastener in accordance with an exemplaryembodiment;

FIG. 4 is a perspective view of a fastener in accordance with anexemplary embodiment;

FIG. 5 is a partial sectional side view of a tube assembly of a driveapparatus and fasteners, in accordance with an exemplary embodiment;

FIG. 6 is a partial sectional perspective view of a distal portion of atube assembly of a drive apparatus and fasteners, in accordance with anexemplary embodiment;

FIG. 7 is a partial sectional bottom view of a distal portion of a tubeassembly of a drive apparatus and fasteners, in accordance with anexemplary embodiment;

FIG. 8 is a partial sectional top view of a distal portion of a tubeassembly of a drive apparatus and fasteners, in accordance with anexemplary embodiment;

FIG. 9 is a partial sectional top view of a distal portion of a tubeassembly of a drive apparatus and fastener, in accordance with anexemplary embodiment;

FIG. 10 is a partial sectional side view of a handle/actuation portionof a drive apparatus in an initial position, in accordance with anexemplary embodiment;

FIG. 11 is an enlargement of portion A-A of FIG. 10, in accordance withan exemplary embodiment;

FIG. 12 is a partial sectional side view of a handle/actuation portionof a drive apparatus in an intermediate position in accordance with anexemplary embodiment;

FIG. 13 is a partial sectional side view of a handle/actuation portionof a drive apparatus in a pre-fired position in accordance with anexemplary embodiment; and

FIG. 14 is a partial sectional side view of a handle/actuation portionof a drive apparatus in a post-fired position in accordance with anexemplary embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, aspects of methods and apparatuses in accordance withvarious exemplary embodiments will be described. As used herein, anyterm in the singular may be interpreted to be in the plural, andalternatively, any term in the plural may be interpreted to be in thesingular.

As used herein, the term “proximal” refers to the portion of a fasteneror fastener drive apparatus closest to the user (i.e., the personinserting the fastener), while the term “distal” refers to the portionof a fastener or fastener drive apparatus furthest from the user.

Exemplary embodiments include a fastener and fastener drive apparatusfor use in surgical procedures. B y way of example, the embodiments areillustrated and described in reference to devices and methods used inconjunction with a hernia repair procedure using a mesh patch. Thus, inthe exemplary embodiments, the fasteners may be referred to as a herniamesh tack and the drive apparatus may be referred to as a tack driveapparatus. However, it is appreciated that the exemplary embodiments areapplicable to various other surgical procedures that require the use ofa fastener and a fastener drive apparatus.

The fasteners of the exemplary embodiments are configured to secure bodytissue to body tissue, or to secure another material, such as a mesh, tobody tissue. For example, a fastener of the exemplary embodiments may beused as a hernia tack that secures a mesh structure to body tissue in ahernia repair procedure. In the exemplary embodiments, the hernia tackis of the axial insertion or “push” type variety and is configured forinsertion upon application of a rapid axial insertion impulse, ascompared to a steady, drawn out insertion force. The hernia tack of theexemplary embodiments includes barbs that enable easy penetration of thetissue with minimal tissue cutting. The fasteners of the exemplaryembodiments can be used in conjunction with a drive apparatus that isconfigured to position a fastener for insertion, and to apply a rapidinsertion impulse to the fastener to permanently insert the fastenerinto a body tissue. Various exemplary embodiments of such fasteners anddrive apparatuses are described in more detail below.

Referring now to FIGS. 1-4, in which like reference numerals identifysimilar or identical elements, the details of an exemplary embodiment ofa fastener 100 are described in greater detail. Generally, the fastener100 has a longitudinal direction L_(F), as indicated by the arrow inFIG. 1. Along the longitudinal direction, the fastener 100 has a distalend 104, and a proximal end 102. In the exemplary embodiments, thedistal end 104 of the fastener 100 generally is the portion of thefastener 100 that is first inserted through the body tissue. In theembodiments, the fastener 100 includes an anchoring element 130 locatednear the distal end 104 of the fastener 100, a head portion 110 locatednear the proximal end 102 of the fastener 100, and a body portion 120located intermediate the two ends 102, 104, connecting the anchoringelement 130 and the head portion 110.

In the exemplary embodiments, the head portion 110 of the fastener 100,can be configured to engage with a body tissue, or other material, suchas a mesh, to hold the tissue or material in place against a bodytissue. As illustrated in FIGS. 1-4, in the exemplary embodiments, theouter surface of head portion 110 of the fastener 100 can include adistal head face 111, a proximal head face 112, an upper head face 113,and a lower head face 114. Each of the faces 111, 112, 113, 114, can beflat or substantially flat surfaces, or they can be arcuate to provide aconcave or convex surface. For example, in the exemplary embodimentillustrated in FIGS. 1-4, upper head face 113 is a flat surface, andlower head face 114 is generally an arcuate surface with a convex shape,such as one formed by a smooth arcuate surface, or a series of adjoiningarcuate or flat facets. In exemplary embodiments, the arc defined by thelower head face 114 can extend at least about 180 degrees and less than360 degrees. In the embodiment illustrated in FIGS. 1-4, the arcuatelower head face 114 provides a 180 degree arc that connects onetransverse edge of the upper head face 113 to the other transverse edgeof the upper head face 113. It is appreciated that any or all of thefaces 111, 112, 113, 114, can be configured to have any desired shape

In various embodiments, the head portion 110 may have a passage 115 thatextends through the head portion 110 from the proximal head face 112 tothe distal head face 111. The passage 115 is configured to enable thefastener 100 to slide along the drive sequencing indexer mechanism, aswill be discussed in more detail later. In exemplary embodiments, thepassage 115 may be shaped in such a way as to compliment the shape ofthe indexer. For example, the passage 115 may be in the form of a boreor a channel that at least partially surrounds the indexer, enabling thefastener 100 to slide along the indexer. For example, in embodiments inwhich the indexer has a rectangular cross-sectional shape, the passage115 may have a corresponding rectangular shaped bore. In other exemplaryembodiments, the passage 115 may be formed as a channel rather than aclosed passage, an that it surrounds only a portion of the indexer. Itwill be understood that the passage 115 may be configured in othersuitable forms and shapes suitable for adapting the fastener to slidealong an indexer. The head portion 110 also may be configured tofacilitate deployment from an applicator.

In various exemplary embodiments, the head portion 110 may include oneor more anchoring devices such as anchor tabs 116 extending from thedistal head face 111. The anchor tabs 116 may be configured to assist inanchoring the mesh or other material in place when the fastener 100 isinserted. The anchor tabs 116 may provide an attachment that securesmore readily to large-holed mesh. For example, during hernia surgery,the anchor tabs 116 may engage the hernia mesh strand to provide a moresecure bond between the mesh and the tissue. The anchor tabs 116 mayhave any shape that would enable the tabs 116 to anchor the mesh. Forexample, in embodiments such as those illustrated in FIGS. 1-4, theanchor tabs 116 may have a triangular shape. It will be understood thatthe anchor tabs 116 may have many alternative shapes.

In various exemplary embodiments, the body portion 120 of fastener 100extends distally from the head portion 110, and has a proximal body end122 joined with the distal head face 111, and a distal body end 121. Inexemplary embodiments, the body portion 120 and the head portion 110 maybe integrally formed to form a single unit. However, it will beunderstood that the body portion 120 and head portion 110 may beseparately formed, and joined together to form the fastener 100. Thebody portion 120 additionally may have an upper body face 123 and alower body face 124. In exemplary embodiments, the upper body face 123and the lower body face 124 may have flat or substantially flatsurfaces, or surfaces that have a partial curve. In some embodiments,the upper body face 123 may be coplanar with the upper head face 113. Insome embodiments, the lower body face 124 may be coplanar with the upperpassage surface 117.

In exemplary embodiments, the distal body end 121 may have one or moreanchoring elements 130. The anchoring element 130 and body portion 120may be integrally formed, or may be separately formed and operablyjoined together. In the embodiment illustrated in FIGS. 1-4, theanchoring element 130 has a pair of barbs 131, 132. Barbs 131,132 mayhave a proximal anchor point 136 that has a width (measured at itswidest point) that is wider than the distal edge 137, which preventsexpulsion or removal of the fastener 100 from the body tissue once thefastener 100 is applied. The barbs 131,132 also may have upper facets133 and lower facets 134 that taper to an angled leading edge 135. Theleading edge 135 is configured to have a cutting portion and astretching portion. When the fastener 100 is inserted, the width of theincision is only as wide as the effective diameter from the proximalends of the cutting portions of the two barbs 131, 132. The stretchingportion serves to widen the incision to admit the tack without furthertissue cutting. When the barbs 131, 132 are fully inserted into thetissue the stretched incision tends to close back up, thereby improvingthe security of the tissue attachment to the inserted fastener 100.

In some embodiments, the first barb 131 is longitudinally offset fromthe second barb 132. Where the impact force is directed through thecenterline of the body portion 120, the offset barb configurationprovides a more acute angle of penetration than with non-offset barbs.It is believed that the offset barb configuration allows for easiertissue penetration by utilizing less force, and also allowing therelationship to the proximal anchor point 136 and the distal body end121 to be geometrically enhanced allowing for increased tissue pull outforce. In addition, it is believed that the offset allows less tissuecutting and stretching relative to the effective width of the twoproximal anchor points 136. While the anchoring element 130 is shownwith two offset barbs 131,132, it will be understood that the anchoringelement 130 may have more barbs or fewer barbs, and the barbsconfiguration may vary.

The fastener 100 and components thereof may be made of any of variousmaterials suitable for insertion into the human body. In variousembodiments, the fastener 100 of the may be made of biocompatiblematerial, such as stainless steel or titanium. In various exemplaryembodiments, the fastener 100 may be made of an absorbable material,such as a polymer. Exemplary absorbable materials include homopolymersand copolymers of lactide, glycolide, polyglycolide, polylactide, orvarious combinations or mixtures thereof. It will be understood thatthere are various suitable polymers and that each exhibits differentabsorption rates, and different shear and tensile strengths when molded.

It will be understood that the fastener 100 will have dimensionssuitable for insertion into the human body, and suitable to provide astable anchoring structure. For example, in various embodiments, thefastener 100 may have an effective overall length (measuredlongitudinally from proximal end 102 to distal end 104) in the range ofabout 4 mm to about 6 mm. In the various embodiments, the diameter ofthe head portion 110 measured transversely at the widest point may be inthe range of about 4 mm to about 10 mm

In exemplary embodiments, the fasteners 100 may be adapted so that aplurality of fasteners 100 may be loaded for application by a driveapparatus 200. In various exemplary embodiments, one or more fasteners100 may be loaded into a fastener drive apparatus 200 and inserted intothe surgical field, either directly, as in the case of open surgery, orthrough a trocar cannula. The fasteners 100 should be sized to becompatible with the size of the drive apparatus 200 and associateddevices. For example, the fasteners 100 may be sized to fit throughdifferent diameter tube assemblies, thus different size trocar ports.Smaller fasteners 100 enable the use of smaller tube assemblies. Forexample, small fasteners 100 having a diameter of about 4 mm makepossible the use of a trocar cannula with a diameter as small as about 5mm.

Turning now to FIGS. 5-14 a drive apparatus 200 according to anexemplary embodiment will be described. In various embodiments, driveapparatus 200 is configured to enable a user such as a surgeon to insertand secure a fastener 100 to a body tissue. Preferably, the driveapparatus 200 is configured for easy manipulation and one-handed use bya user. In an exemplary embodiment, one or more fasteners 100 may beloaded into the drive apparatus 200, so that they may be individuallydeployed by the drive apparatus 200. In exemplary embodiments, the driveapparatus 200 may have a sequencer or indexer 260 to align and shift thefasteners 100 inside the drive apparatus 200. The drive apparatus 200further may have a driver mechanism 270 to provide a rapid impulse forceto a fastener 100, ejecting the fastener 100 from the drive apparatus200 with sufficient force to insert the fastener 100 into a body tissue.

As illustrated in FIG. 10, in various exemplary embodiments, the driveapparatus 200 has a handle/actuation assembly 210 and a tube assembly250. The tube assembly 250 may be configured to house a plurality offasteners 100. The tube assembly 250 has a distal end 254, from whichthe fasteners 100 are ejected. The handle/actuation assembly 210provides a handgrip 214 that enables the user to manipulate the driveapparatus 200. In exemplary embodiments, the handle/actuator assembly210 further includes a trigger 216 that, when triggered, actuates theindexer 260, the driver mechanism 270, or both.

In exemplary embodiments, the tube assembly 250 has an elongated tubeportion 252, extending in a longitudinal direction, L_(T), and having alength Y. At its proximal end, the elongated tube portion 252 is joinedwith the handle/actuation assembly 210. The distal end of the elongatedtube portion 252 coincides with the distal end 254 of the tube assembly250, from which the one or more fasteners 100 are ejected. The length Yof the elongated tube portion 252, measured from its proximal end to itsdistal end, may be selected according to the intended use of the driveapparatus 200. For example, in an embodiment in which the driveapparatus 200 is used in laparoscopic procedures, the elongated tubeportion 252 may have a length of about 12 inches to about 15 inches. Inan embodiment in which the drive apparatus 200 is used fornon-laparoscopic applications, a length of about 4 inches to about 9inches may be more suitable. As guided by the disclosure herein, it willbe understood by one of ordinary skill in the art how to select asuitable length for the elongated tube portion 252, depending on theintended use of the drive apparatus 200.

Turning now to FIGS. 5-9, the tube assembly 250 will be described inmore detail. As illustrated in the figures, in various exemplaryembodiments, the tube assembly 250 houses an indexer 260, a driver 270,and a spacer. Generally speaking, the indexer 260 serves the purpose ofindexing the one or more fasteners 100 within the tube assembly 250, andmoving them toward the distal end 254 of the tube assembly 250 so thatthey may be ejected. The driver 270 generally serves the purpose ofejecting the distal-most fastener 100 from the distal end 254 of thetube assembly 250. The spacer generally serves the purpose of aligningthe driver 270, the indexer 260 within the tube assembly 250. Each ofthese devices is explained in more detail herein.

In various exemplary embodiments, the indexer 260 may have an elongatedmember 262 adapted to temporarily secure the fasteners 100 within thetube assembly 250, and to index the fasteners 100 in a distal directionalong the longitudinal direction L_(T) of the tube assembly 250. Forexample, the indexer 260 may have an elongated member 262 that isadapted to fit within the passage 115 of the one or more fasteners 100loaded in the drive apparatus 200. It will be understood that in otherexemplary embodiments, the elongated member 262 may be disposed alongone or more sides of the fasteners 100, rather than through the centralpassage 115 of the fasteners 100.

In exemplary embodiments, the elongated member 262 may move in adirection substantially parallel to the longitudinal direction L_(T) ofthe tube assembly 250. The elongated member 262 may have one or morefeatures that enable it to transport the one or more fasteners 100within the tube assembly 250. For example, the indexer 260 may furtherhave a plurality of indexer engagers 264, 266, that temporarily securethe fasteners 100 to the indexer 260, so that the fasteners 100 movewith the indexer 260. In the exemplary embodiment illustrated in FIG. 6,the indexer 260 has an elongated member 262 that is coupled with adistal index engager 264 and a proximal index engager 266. The elongatedmember 262 fits inside the passage 115 of one or more fasteners 100 (seeFIGS. 5 and 7). The proximal index engager 266 is configured to engagewith the proximal head face 112 of fastener 100. The distal indexengager 264 is configured to temporarily engage with the distal headface 111 of fastener 100. In this configuration, the index engagers 264,266, temporarily secure the fastener 100 to the elongated member 262 sothat the fasteners 100 move with the elongated member 262.

In various embodiments, the indexer 260 may be configured to enable thefasteners 100 to move independently from the indexer 260. For example,index engagers 264, 266, may be configured to enable the fasteners 100to slide in a distal direction along the elongated member 262, butprevent the fasteners 100 from moving in a proximal direction. In theexemplary embodiment illustrated in FIG. 6, the proximal index engager266 has two angled arms 267 that extend toward the proximal head face112 of the fastener 100. At its widest point, which is adjacent theproximal head face 112, the arms 267 render the proximal index engager266 wider than the passage 115 of the fastener 100, providing a stopthat prevents the proximal movement of the fastener 100 relative to theindexer 260. The arms 267 are sufficiently flexible to enable thefastener 100 to slide over the proximal index engager 266 in a distaldirection. However, once the fastener 100 has slid past the proximalindex engager 266, the arms 267 shift back to their initialconfiguration, preventing the proximal movement of the fastener 100relative to the indexer 260. In the exemplary embodiment of FIG. 6, thedistal index engager 264 has two arms 265 extending toward the distalhead face 111 of the fastener 100. The arms 265 have rounded ends thatare capable of limiting the distal movement of the fastener 100 relativeto the indexer 260, but when a force that exceeds a predeterminedthreshold is applied to the fastener 100, the arms 265 flex inward,enabling the fastener 100 to slide in a distal direction over the distalindex engager 264. It will be understood how to specify thepredetermined threshold, consistent with the guidance provided herein.

In various exemplary embodiments, the tube assembly 250 may beconfigured to limit the proximal movement of the fasteners 100 relativeto the tube assembly 250. In the exemplary embodiment illustrated inFIG. 6, the elongated tube portion 252 may have, along its innersurface, one or more lance tabs 256 that provide an interference pointalong the elongated tube portion 252, preventing the proximal movementof the fasteners 100 relative to the elongated tube portion 252. Forexample, in the embodiment illustrated in FIG. 6, lance tabs 256 projectfrom the inner surface of the elongated tube portion 252, at an angletoward the distal end of the elongated tube portion 252. At its distalend, the lance tabs 256 reduces the width of the elongated tube portion252 so that it is narrower than the width of the head portion 110 of thefastener 100, providing a stop that prevents the fastener 100 frommoving in a proximal direction relative to the elongated tube portion252. However, the lance tabs 256 are capable of flexing outward when thefastener 100 slides past them in a distal direction. In exemplaryembodiments, the lance tabs 256 may be provided in pairs, disposed onopposite sides of the elongated tube portion 252. In certainembodiments, the lance tabs 256 are made of punch-outs on the elongatedtube portion 252, that are flexed or bent toward the center of theelongated tube portion 252. In this configuration, the lance tabs 256are integral with the elongated tube portion 252. However, it will beunderstood that the lance tabs 256 may be separately formed, andattached to the inner surface of the elongated tube portion 252, toprovide projections, flanges, or other suitable structures along theinterior of the elongated tube portion 252. It will be understood thatother features may be provided as an alternative to, or in addition tothe lance tabs 256, to limit the proximal movement of the fasteners 100relative to the elongated tube portion 252.

In various exemplary embodiments the indexer 260 is configured to indexmultiple fasteners 100 within the elongated tube portion 252. FIG. 5illustrates aside elevation view of an exemplary tube assembly 250, witha portion of the elongated tube portion 252 cut away to reveal theinternal elements. FIG. 7 illustrates a bottom view of an exemplary tubeassembly 250, with a portion of the elongated tube portion 252 cut awayto reveal the internal elements. In these exemplary embodiment, threefasteners 100 a, 100 b, and 100 c are shown, but it will be understoodthat the drive apparatus 200 may be configured to hold more, or fewer,fasteners 100. Indexer 260 preferably has a number of proximal indexengagers 266, and distal index engagers 264 that is equal to or greaterthan the number of fasteners 100 loaded in the drive apparatus 200, sothat each fastener 100 is secured to the indexer 260 prior to beingexpelled from the drive apparatus 200. Indexer 260 has an elongatedmember 262, that extends through the passage (not shown) of therespective head portions 110 a, 110 b, 110 c, of each of the fasteners100 a, 100 b, 100 c. Adjacent the distal head face (111 a, 111 b, 111 c)of each head portion is a distal index engager 264 a, 264 b, 264 c, andadjacent each proximal head face (112 a, 112 b, 112 c) is proximal indexengager 266 a, 266 b, 266 c. Lance tabs 256 are located on the innersurface of the elongated tube portion 252, and are shown abutting theproximal head faces (112 a, 112 b, 112 c) of the fasteners 100 a, 100 b,100 c.

The operation of the indexer 260 will now be described in reference tothe embodiments of FIGS. 5, 7, and 8. For purposes of discussion, theindexer 260 in FIGS. 5 and 7 is illustrated in its initial,proximal-most position (i.e., the position it holds during the initialstage of operation),which is also its reset position; the indexer 260 inFIG. 8 is illustrated in its distal-most position, which is its positionat the pre-firing stage. From this position, the indexer 260 may bedescribed as having a cyclical movement, during which it may movedistally from its initial position to its pre-firing stage position (thedistal stroke) and then proximally back to the initial position (theproximal stroke), completing a full cycle of movement.

In an exemplary embodiment, during the indexer's 260 distal stroke, theindexer 260 moves the fasteners 100 a, 100 b, and 100 c which are heldin place by the respective index engagers 264 a-c and 266 a-c. Thedistal stroke of the indexer 260 may end when the fasteners 100 a, 100b, 100 c advance beyond the next lance tab 256, as illustrated in FIG.8. This places the distal-most fastener 100 a in its firing positionrelative to the tube assembly 250; i.e., the position at which it isready to be ejected from the tube assembly 250, such as by driver 270.After the indexer 260 reaches its pre-firing stage position, it maycommence its proximal stroke. During the indexer's 260 proximal stroke,the lance tabs 256 prevent the proximal movement of the fasteners 100 a,100 b, 100 c relative to the tube assembly 250, as described above.Therefore, the proximal movement of the indexer 260 creates a forcebetween the distal index engagers 264 a, 264 b, 264 c, and therespective distal head faces 111 a, 111 b, 111 c. When this forcereaches a certain threshold, the distal index engagers 264 a, 264 b, 264c will flex inward and slide through the passage (not shown) of therespective fastener 100 a, 100 b, 100 c, enabling the indexer 260 tocontinue its proximal stroke without moving the fasteners 100 a, 100 b,100 c. The indexer's 260 proximal stroke continues until index engagers264 a-c and 266 a-c, engage with the next proximal fastener (e.g., indexengagers 264 a and 266 a may engage with next proximal fastener 100 b,and index engagers 264 b and 266 b may engage with next proximalfastener 100 c, etc.) At this point, the indexer 260 has returned to itsinitial position, completing a full cycle. In exemplary embodiments, thelength of the distal stroke of the indexer 260 is about equal to thedistance between adjacent lance tabs 256. The indexer 260 may repeatthis cycle one or more times, advancing all of the fasteners 100distally within the tube assembly 250 as described above.

In exemplary embodiments, the indexer 260 is operably coupled with thehandle/actuation assembly 210 so that movement of the indexer 260 iscontrolled by one or more mechanisms within the handle/actuationassembly 210, which is described in more detail below.

In various embodiments, the driver assembly 200 has a driver 270 that isconfigured to provide an ejection force to a fastener 100, expelling thefastener 100 from the distal end 254 of the tube assembly 250. Inexemplary embodiments, the vector of the ejection force is substantiallyparallel to the longitudinal direction L_(T) of the tube assembly 250,and the force is applied to the fastener 100 so that the fastener 100 isexpelled in a direction that is substantially parallel to thelongitudinal direction L_(T) of the tube assembly 250. In exemplaryembodiments, the ejection force is sufficient to insert the fastener 100into a body tissue. In certain embodiments, the ejection force is animpulse force that fires the fastener 100 from the distal end 254 of thetube assembly 250.

As illustrated in FIG. 5, in various exemplary embodiments the driver270 may be an elongated member, such as a beam or shaft, that terminateson its distal end at an ejector portion 276. The elongated driver membermay have a rectangular cross section; however, it will be understoodthat the elongated driver member may have any of a number of suitabledifferent shapes and configurations. In exemplary embodiments, theelongated member of the driver 270 may have a straight portion 272, anangular portion 274 that is angled downward toward the ejector portion276. In this configuration, the straight portion 272 of the driver 270may be offset from the pathway of movement of the fasteners 100 a, 100b, 100 c, while the ejector portion 276 delivers the ejection forcealong the pathway of movement of the fasteners 100 a, 100 b, 100 c. Itwill be understood that the driver 270 may have other physicalconfigurations consistent with its function of delivering the ejectionforce to the fasteners 100 a, 100 b, 100 c.

The operation of the driver 270 will now be described in reference tothe embodiments of FIGS. 5, 7, 8, and 9. For purposes of discussion, thedriver 270 in FIGS. 5 and 7 is illustrated in its initial position (alsothe reset position); the driver 270 in FIG. 8 is illustrated in itspre-firing position, and the driver 270 in FIG. 9 is illustrated in itsfiring position. From its initial position, the driver 270 is at or nearits distal-most position. From this position, the driver 270 may bedescribed as having a cyclical movement, during which may moveproximally toward the handle/actuation assembly 210 of the driverapparatus 200 (the proximal stroke) and then distally back to theinitial position (the distal stroke), completing a full cycle ofmovement. In exemplary embodiments, the driver 270 may move in adirection substantially parallel to the longitudinal direction L_(T) ofthe tube assembly 250.

In the exemplary embodiment illustrated in FIG. 5, the driver 270 isshown in its initial position (also reset position) with the ejectorportion 276 of the driver 270 adjacent the distal end 254 of the tubeassembly 250. During its proximal stroke, the driver 270 retracts awayfrom the firing position 258 of the tube assembly 250, while the indexer260 indexes the distal-most fastener 100 into the firing position 258.At the end of its distal stroke, driver 270 is in its pre-firingposition, as illustrated in FIG. 8. In the pre-firing position, ejectorportion 276 of the driver 270 is adjacent to the proximal head surface112 of the fastener 100 that is in the firing position 258. During itsdistal stroke, the driver 270 delivers an ejection force (e.g., animpulse force) to the distal-most fastener 100 located in the firingposition 258. As illustrated in FIG. 9, when the driver 270 is in itsfiring position, it is ejecting this fastener 100 from the distal end254 of the tube assembly 250. In exemplary embodiments, the driver 270ejects the fastener 100 with sufficient force and speed that thefastener 100 is securely inserted into the surgical field, such as intoa hernia mesh or a body tissue. Once the fastener 100 is ejected by thedriver 270, the driver 270 is in its initial position (or resetposition), as illustrated in FIGS. 5 and 7,

As illustrated in FIG. 5, the driver 270 may be disposed near the upperportion of the elongated tube portion 252, so that it is above theindexer 260, and fasteners 100. In this configuration, the straightportion 272 of the elongated member is generally disposed above thefasteners 100. In various embodiments, the ejector portion 276 of thedriver 270 may move up and down during the driver's 270 cycle ofmovement. For example, in the driver's 270 proximal stroke, the driver270 may flex or pivot upward from its initial position so that theejector portion 276 moves out of the indexing pathway of fasteners 100.During the distal stroke of the driver 270, the ejector portion 276 maydrop down behind the fastener 100 that is in the firing position 258, sothat the ejector portion 276 pushes the fastener 100 along a path ofmovement that is parallel to the longitudinal direction L_(T) of thetube assembly 250.

While the embodiments thus far have been described with respect to adriver 270 that is located above the fasteners 100, it will beunderstood that the driver 270 may be located instead in a differentarea or region, such as above or to one or more sides of the fasteners100, or the driver 270 may be aligned with the path of movement of thefasteners 100.

In exemplary embodiments, the direction and speed of the movement of thedriver 270 is independent of the movement of the indexer 260. Forexample, the driver 270 may be in its distal stroke when the indexer 260is in its proximal stroke. In addition, during their respective distalstrokes, the rate of speed of the driver 270 may be faster than thespeed of the indexer 260.

In exemplary embodiments, the driver 270 is operably coupled with thehandle/actuation assembly 210 so that movement of the driver 270 iscontrolled by one or more mechanisms within the handle/actuationassembly 210, which is described in more detail below.

In exemplary embodiments, the drive apparatus 200 may have a spacerdisposed with in the tube assembly 250, in the elongated tube portion252. The spacer may be configured to maintain the alignment of thedriver 270, the indexer 260, and the fasteners 100, within the elongatedtube portion 252. In exemplary embodiments, the spacer is stationaryrelative to the elongated tube portion 252. However, it will beunderstood that the spacer may move relative to one or more componentsof the tube assembly.

As previously indicated, the drive apparatus 200 may have ahandle/actuation assembly 210 that provides a housing 212, a handgripportion 214, and a trigger 216. FIG. 10 illustrates a section view of ahandle/actuation assembly 210 according to an exemplary embodiment. Thehousing 212 defines an interior space that houses the mechanicalelements of the handle/actuation assembly 210. It will be understoodthat only one side of the housing 212 is illustrated in FIG. 10, andthat the complete housing 212 may include a mirror image portion,fastened to the illustrated portion, such as by screws or othermechanical fasteners, or by welding. The distal end of the housing 212has a tube assembly opening 220, through which the tube assembly 250 isinserted so that it may be operably coupled with one or more mechanicalelements inside the housing 212. The proximal portion of thehandle/actuation assembly 210 comprises a handgrip portion 214, which isconfigured for easy manipulation for a user. It will be understood howto design the handgrip portion 214 with various contours and featuressuitable for this purpose.

In exemplary embodiments, a trigger 216 is pivotably coupled with thehandle/actuation assembly 210 at trigger pivot 218, located at leastpartially within housing 212. Trigger 216 may be configured so that itmay be easily manipulated by a user from outside of the housing. Forexample, in the embodiment illustrated in FIG. 10, the trigger 216 maybe a lever arm adjacent the handgrip portion 214. The trigger 216 may bemanipulated by the user, for example, by squeezing the lever arm towardthe handgrip portion 214, causing the trigger 216 to rotate in acounter-clockwise direction about trigger pivot 218. It will beunderstood that trigger 216 may comprise one of various other triggeringdevices now known or later developed, consistent with the teachingsprovided herein. In exemplary embodiments, trigger 216 is biased towardthe untriggered position. For example, the trigger 216 may be biased byusing a torsion spring, a spring clip, or other suitable devices. One ofordinary skill in the art would be able to design and configure variousdevices suitable for biasing the trigger 216, using the guidanceprovided herein.

In exemplary embodiments, trigger 216 is operably coupled with at leastone actuator, such that manipulation of the trigger 216 actuates theindexer 260, the driver 270, or both. In exemplary embodiments, trigger216 is operably coupled with an indexer actuator assembly 230 that isoperably coupled with (either directly or indirectly) the indexer 260.In exemplary embodiments, trigger 216 is operably coupled with a driveractuator assembly 240 that is operably coupled with (either directly orindirectly) the driver 270. In the various embodiments, indexer actuatorassembly 230 and driver actuator assembly 240 are disposed at leastpartially within housing 212, and are operably coupled with the tubeassembly 250, which at least partially extends from the tube opening 220in housing 212.

In exemplary embodiments, indexer actuator assembly 230 is operablycoupled with the indexer 260, to provide the mechanical action necessaryto move the indexer 260 through its full cycle of motion. The indexeractuator assembly 230 of an exemplary embodiment will now be describedwith reference to FIGS. 10-13. In exemplary embodiments, the indexeractuator assembly 230 includes a cam 232 that is operably coupled withthe trigger 216 and translates the rotational movement of the trigger216 about the trigger pivot 218, into longitudinal movement of pusherarm 231. FIG. 10 illustrates the exemplary indexer actuator assembly 230at or near its initial position (also its reset position), in which thetrigger 216 has not been squeezed, and the pusher arm 231 is at itsproximal-most position. In the exemplary embodiment, as trigger 216 issqueezed, the trigger 216 pivots in a counter clockwise direction abouttrigger pivot 218. When the trigger 216 pivots, the cam 232 causes thepusher arm 231 to move in a distal direction. FIG. 12 illustrates theexemplary indexer actuator assembly 230 in this intermediate position,in which the trigger 216 has been squeezed, so that it has partiallyrotated about trigger pivot 218, and cam 232 has engaged with pusher arm231 to push it in a distal direction. The indexer 260 is operablycoupled with indexer actuator assembly 230, such that distal movement ofthe pusher arm 231 causes distal movement of the indexer 260 (i.e., thedistal stroke of the indexer 260). When the trigger 216 is fullysqueezed, as illustrated in FIG. 13, the pusher arm 231 reaches itsdistal-most position, and the indexer 260 completes its distal stroke.When the trigger 216 is thereafter released, a biasing force acts on theindexer actuator assembly 230 to move the pusher arm 231 in a proximaldirection, thereby causing the indexer 260 to move in its proximalstroke. The biasing force may be provided by one or more biasing devicesthat are operably coupled with the trigger 216, the trigger pivot 218,the cam 232, the pusher arm 231, or any combination thereof. The biasingforce is sufficient to return the pusher arm 231 (and therefore theindexer 260) to its initial position (e.g., FIG. 10).

In exemplary embodiments, drive actuator assembly 240 is operablycoupled with the driver 270, to provide the mechanical action necessaryto move the driver 270 through its full cycle of motion. The driveractuator assembly 240 of an exemplary embodiment will now be describedwith reference to FIGS. 10-13. In exemplary embodiments, the driveractuator assembly 240 includes a slideable plunger 245 that is slidablycoupled with a central shaft 247, so that the plunger 245 may move in aproximal and distal direction along the shaft 247. FIG. 10 illustratesthe exemplary driver actuator assembly 240 at or near its initialposition (or reset position), in which the pusher arm 245 is at itsdistal-most position. The driver 270 may be coupled with the driveractuator assembly 240 such that proximal movement of the slideableplunger 245 causes proximal movement of the driver 270 (e.g., itsproximal stroke), and distal movement of the slidable plunger 245 causesdistal movement of the driver 270 (e.g., its distal stroke). A biasingspring 248 biases the plunger 245 toward the distal end of the shaft247, and therefore biases the driver toward the distal end 254 of thetube assembly 250.

In exemplary embodiments, the slideable plunger 245 of driver actuatorassembly 240 is operably coupled with the trigger 216, so that thesqueezing the trigger 216 moves the slideable plunger 245 (and likewisethe driver 270) in a proximal direction. For example, scissor beams 241may be attached at one end to the handle/actuation assembly 210, such asat a beam pivot 242; the free end 244 of the scissor beams 241 may beoperably coupled with the proximal end of the slideable plunger 245,such as at lip 246. The scissor beams 241 are joined at elbow joint 243,and are biased toward a closed position, such as with a torsion springor other suitable device. Elbow joint 243 may be operably coupled withthe trigger 216, such that squeezing of the trigger 216 causes thescissor beams 241 to straighten at the elbow joint 243, so that the freeend 244 of the beams 241 pushes on the lip 246 of the slideable plunger245, causing plunger 245 to slide in a proximal direction along shaft247. FIG. 12 illustrates the driver actuator assembly 240 in anintermediate position, in which the trigger 216 has not been fullysqueezed, the scissor beams 241 are partially straightened or extended,and the plunger 245 has moved in a proximal direction along the centralshaft 247. The proximal movement of the plunger 245 causes the driver270 to move along its proximal stroke. When the trigger 216 is fullysqueezed, the plunger 245 reaches a pre-firing position (illustrated inFIG. 13), at which point the plunger 245 is at its proximal-most pointand the beams 241 are still engaged with the lip 246. After the driveractuation assembly 240 reaches the pre-firing position, when the trigger216 is further squeezed, the beams 241 are configured to automaticallydisengage from the plunger 245, enabling the biasing spring 248 to forcethe plunger 245 to slide in a distal direction. FIG. 14 illustrates thedriver actuator assembly 240 in a post-firing position, just after thescissor beams 241 have released from the plunger 245, and the plunger245 has moved in a distal direction along central shaft 247. The distalmovement of the plunger 245 causes the driver 270 to move along itsdistal stroke, thereby “firing” fastener 100, or ejecting it from thedistal end 254 of the tube assembly 250. In exemplary embodiments thebiasing spring 248 is configured to deliver an impulse force to theplunger 245 toward its initial distal-most position. This impulsemovement is translated along the driver 270, to the ejector portion 276of the driver 270, which delivers the impulse force to the fastener 100that is in the firing position 258 within the tube assembly 250, therebyejecting the fastener 100 with sufficient force to insert the fastener100 into the surgical field, such as through a hernia mesh or bodytissue. One of ordinary skill in the art would understand how toconfigure spring 248 to exert such a force, and would be able to applysuch a spring to a drive apparatus 200, using the guidance providedherein.

In various exemplary embodiments, when the trigger 216 is released afterit has been fully squeezed (so as to deliver the impulse force), thedriver actuation assembly 240 returns to its initial position, asillustrated in FIGS. 10 and 11. During the return to the initialposition, the scissor beams 241 return to their initial position, andthe free end 244 of the beams 241 automatically re-engages with the lip246 of plunger 245, so that the driver actuator assembly 240 is readyfor another cycle of motion.

In various exemplary embodiments, the handle/actuation assembly 210 alsoincludes a trigger lock 233, that prevents the trigger 216 from beingreleased before it reaches its fully squeezed position, which may causethe inadvertent sequencing of fasteners 100, and release of the driver270. For example, the trigger lock 233 may include a device thatmechanically interferes with the rotation of the trigger 216 about pivot218. One of ordinary skill in the art will understand the variousdevices that could be used as a trigger lock, and would be able to applythem to the handle/actuation assembly 210 using the guidance providedherein.

In exemplary embodiments, trigger 216 is operably coupled with bothindexer actuator assembly 230, and driver actuator assembly 240, so thatmanipulation of the trigger 216 actuates both assemblies 230, 240. Invarious embodiments, the indexer 260 and driver 270 are independentlycoupled with the trigger 216 so that the driver 270 and the indexer 260may be moved independently of each other when the trigger 216 istriggered. However, in exemplary embodiments, from the perspective ofthe user, the triggered actions of the drive apparatus 200 may appear tobe simultaneous.

The method of operation of the drive apparatus 200 to deploy a fastener100 may best be understood in reference to the exemplary embodimentsillustrated in FIGS. 10-14. In exemplary embodiments, the driveapparatus 200 is manually operated by a user, such as a surgeon, whomanipulates the drive apparatus 200 such as by grasping the handgripportion 214, so as to position the distal end 254 of the tube assembly250 adjacent the location where the fastener 100 is to be inserted. Theuser then squeezes the trigger 216, pulling it toward the handgripportion 214, which causes the drive apparatus 200 to advance through aseries of stages of operation described in more detail below.

FIG. 10 illustrates an exemplary drive apparatus 200 in its initialstage, in which the trigger 216 has not been squeezed. In its initialposition, plunger 245 of driver actuator assembly 240 is in itsdistal-most position, and corresponding driver 270 is in its distal-mostposition, with ejector portion 276 adjacent the distal end 254 of tubeassembly 250. In its initial position, pusher arm 231 of the indexeractuator assembly 230 is in its proximal-most position, andcorresponding indexer 260 is in its proximal-most position. In theinitial position, no fastener 100 is in the firing position 258 of thetube assembly 250.

In the exemplary embodiment, as the trigger 216 is squeezed, the driveapparatus 200 moves into an intermediate stage, illustrated in FIG. 12.In the intermediate position, plunger 245 of driver actuator assembly240 has moved in a proximal direction, and corresponding driver 270 hasprogressed into its proximal stroke, in which the ejector portion 276 ofthe driver 270 moves away from the distal end 254 of tube assembly 250.In its intermediate position, pusher arm 231 of the indexer actuatorassembly 230 has moved in a distal direction, and corresponding indexer260 has moved in a distal direction within the tube assembly 250,indexing fasteners 100 in a distal direction toward the distal end 254of the tube assembly 250.

Just prior the trigger 216 being fully squeezed, the drive apparatus 200moves into a pre-firing stage, illustrated in FIG. 13. In the pre-firingposition, pusher arm 231 of the indexer actuator assembly 230 is in itsdistal-most position, and corresponding indexer 260 has finished itsdistal stroke, so that the distal-most fastener 100 is in the firingposition 258 within the tube assembly 250. In the pre-firing position,plunger 245 of the driver actuator assembly 240 has moved to itsproximal-most position, and corresponding driver 270 has completed itsproximal stroke, whereby the ejector portion 276 of the driver 270 islocated adjacent the proximal head face 112 of distal-most fastener 100.

Just past the pre-firing position, as the user continues to squeeze thetrigger 216 to its fully squeezed position, the scissor beams 241release from lip 246 of plunger 245. Once released, the plunger 245retracts to its distal-most position, under the compressive force ofspring 248. This motion causes the corresponding driver 270 to fire oreject the distal-most fastener 100 that has been loaded by indexer 260into the firing position 258 of tube assembly 250. In the exemplaryembodiment, after the trigger 216 is fully squeezed, and the driver 270fires the distal-most fastener 100 from the tube assembly 250, the driveapparatus 200 moves into a post-firing stage, illustrated in FIG. 14. Inthe post-firing position, scissor beams 241 have released plunger 245,which has retracted to its distal-most position, and correspondingdriver 270 has ejected the distal-most fastener 100 from the firingposition 258, through the distal end 254 of the tube assembly 250. Inthe post-firing position, the pusher arm 231 of the indexer actuatorassembly 230 is at or near its distal-most position, and correspondingindexer 260 is at or near its distal-most position.

In the exemplary embodiment, when the trigger 216 is released afterbeing fully squeezed, the drive apparatus 200 returns to its initialposition, illustrated in FIG. 10. When released, the driver actuatorassembly 240 returns to its initial position with the plunger 245 in itsdistal-most position, and the scissor beams 241 retract to their initialposition, re-engaging with the plunger 245. When released, trigger 216rotates in a clockwise direction about trigger pivot 218, and cam 232and pusher arm 231 move in a proximal direction until pusher arm 231reaches its proximal-most position. When pusher arm 231 moves in theproximal direction, the indexer 260 completes its proximal stroke untilthe indexer engagers 264, 266 engage with the next proximal fasteners100.

From the perspective of the user, the triggered actions of the driveapparatus 200 appear to be simultaneous. In other words, the user placesthe distal opening 254 of the tube assembly 250 adjacent the portion ofthe hernia mesh to be fastened and squeezes the trigger 216 to itsfullest extent in one continuous motion. This causes the distal fastener100 to be ejected from the tube assembly 250 and into the hernia meshand underlying body tissue. Upon release of the trigger 216, the driveapparatus 200 returns to its initial position and is immediately readyto dispense another fastener 100.

Many embodiments and adaptations of the present invention, other thanthose herein described with reference to the exemplary embodiments, willbe apparent to those skilled in the art by the foregoing description,without departing from the substance or scope of the invention. Whilethe present invention has been described herein in detail in relation toits exemplary embodiments, it is to be understood that this disclosureis only illustrative and exemplary of the present invention.Accordingly, the foregoing disclosure is not intended to be construed soas to limit the present invention or otherwise to exclude any other suchembodiments, adaptations, variations, modifications, and equivalentarrangements. The claimed invention is limited only by the followingclaims.

1. A fastener for attaching to a body tissue, having a longitudinaldirection, a proximal end, and a distal end, and comprising: a headportion disposed near the proximal end of the fastener, and having aproximal surface, a distal surface, and a passage that extends throughthe head portion from the proximal surface to the distal surface; a bodyportion extending from the distal surface of the head portion in thelongitudinal direction; and an anchoring element extending from the bodyportion, and comprising at least one barb at least partially disposedadjacent the distal end of the fastener.
 2. The fastener of claim 1,wherein the at least one barb has a proximal end and a distal end, andwherein the barb's proximal end is wider than the barb's distal end, asmeasured in a direction orthogonal to longitudinal direction.
 3. Thefastener of claim 1, wherein the at least one barb further comprises anupper facet and a lower facet, said facets tapering to an angled leadingedge.
 4. The fastener of claim 1, wherein the anchoring elementcomprises two barbs disposed on opposite sides of the fastener.
 5. Thefastener of claim 4, wherein the two barbs are longitudinally offsetfrom each other.
 6. The fastener of claim 2, wherein the anchoringelement comprises two barbs disposed on opposite sides of the fastener.7. The fastener of claim 6, wherein distal ends of the two barbs arelongitudinally offset from each other.
 8. The fastener of claim 1,wherein the head portion further comprises at least one anchor tabdisposed on the distal surface of the head portion.
 9. The fastener ofclaim 1, wherein the passage is a bore.
 10. The fastener of claim 9,wherein the bore is rectangular.
 11. The fastener of claim 1, whereinthe fastener is made of absorbable material.
 12. The fastener of claim1, wherein the passage is a channel.
 13. The fastener of claim 1,wherein the distal head face and proximal head face are substantiallyflat surfaces.
 14. An applicator for applying a barbed fastener to abody tissue, the applicator comprising: an elongated tubular portionhaving a longitudinal axis extending from a proximal end to a distal endand having a tube interior accessible by proximal and distal tubeopenings, the tube interior being sized and configured for receiving thebarbed fastener; an indexer disposed at least partially inside the tubeinterior, the indexer having an elongated indexer body member and afastener engaging portion adapted to engage the barbed fastener and movethe barbed fastener from an initial fastener position in the tubeinterior to a firing position as the indexer moves from a firstlongitudinal position to a second, more distal longitudinal position;and a driver disposed at least partially inside the tube interior, thedriver having a driver engaging portion at its distal end, the driverengaging portion being adapted to engage the barbed fastener in thefiring position and selectively apply an ejection force to the barbedfastener, thereby ejecting the barbed fastener from the tube interiorthrough the distal opening.
 15. The applicator of claim 14, wherein theejection force is applied to the barbed fastener by the driver as thedriver is moved distally from a pre-firing driver position to adistal-most driver position adjacent the distal tube opening.
 16. Theapplicator of claim 15 wherein a biasing force is applied to the driverby a spring when said driver is in the pre-firing driver position, saidbiasing force serving to bias the driver toward the distal-most driverposition.
 17. The applicator of claim 15 wherein the applicator isconfigured for operation through a repeatable operation cyclecomprising: an initial stage, in which the indexer is in its firstlongitudinal position and the driver is in its distal-most position; apre-firing stage, in which the indexer is in its second, more distallongitudinal position and the driver is in its pre-firing position; anda post-firing stage, in which the indexer is in its second, more distallongitudinal position, and the driver is in its distal-most position.18. The applicator of claim 17, wherein the indexer and driver areoperably coupled with an actuation assembly configured to selectivelycontrol and coordinate movement of the indexer and driver from theirinitial stage positions to their pre-firing stage positions, from theirpre-firing stage positions to their post-firing stage positions, andfrom their post-firing stage positions back to their initial stagepositions.
 19. The applicator of claim 18, wherein the actuationassembly comprises a trigger configured for rotational movement betweenan initial trigger position, a pre-firing trigger position and apost-firing trigger position, the trigger and actuation assembly beingadapted so that movement of the trigger from the initial triggerposition to the pre-firing trigger position causes the indexer anddriver to move from their initial stage positions to their pre-firingstage positions, further movement of the trigger to the post-firingtrigger position causes the indexer and driver to move from theirpre-firing stage positions to their post-firing stage positions, andmovement of the trigger back to the initial trigger position causes theindexer and driver to move from their post-firing stage positions backto their initial stage positions.
 20. The applicator of claim 14,wherein the barbed fastener comprises a head portion having a fastenerpassage formed therethrough and wherein the elongated indexer bodymember is configured for slidable disposition through the fastenerpassage.
 21. The applicator of claim 14, wherein: the tube interior issized and configured for receiving one or more additional fastenerssubstantially identical to the barbed fastener, the additional fastenersbeing serially positionable within the tube interior proximal to thebarbed fastener along the longitudinal axis, the indexer has one or moreadditional engaging portions adapted to engage the additional fastenersand to move each of the additional fasteners from a first longitudinalfastener position to a second more distal longitudinal fastener positionat the same time the indexer moves the barbed fastener from its initialfastener position to its firing position.
 22. The applicator of claim21, wherein the second longitudinal position of the distal-most of theadditional fasteners is the same as the initial fastener position of thebarbed fastener.
 23. The applicator of claim 21 further comprising:means for preventing the additional fasteners from moving in a proximaldirection when the indexer returns from its second, more distallongitudinal position to the first longitudinal position.
 24. Theapplicator of claim 21, wherein the elongated tube portion comprises oneor more lance tabs projecting inward from an inner surface of theelongated tube portion at an angle toward the distal end of theelongated tube portion and capable of flexing outward, the lance tabsbeing configured to engage and prevent the proximal movement of theadditional fasteners while allowing their distal movement by theindexer.
 25. A method of applying a fastener to a pre-determined targetinsertion point on a body tissue, comprising: providing a fastenerhaving a head portion having a passage formed therethrough, an anchoringelement configured for engaging the body tissue, and a body portionextending distally from the head portion to connect the anchoringelement thereto; providing a fastener applicator comprising an elongatedtubular portion having a longitudinal axis extending from a proximal endto a distal end and having a tube interior accessible by proximal anddistal tube openings, an indexer disposed at least partially inside thetube interior, the indexer being adapted to selectively move thefastener from an initial position to a firing position adjacent thedistal tube opening, and a driver disposed at least partially inside thetube interior, the driver being adapted to engage the fastener in thefiring position and selectively apply an ejection force to the fastener;placing the fastener in the initial position within the tube interior;causing the indexer to selectively move the fastener from the initialposition to the firing position; positioning the distal opening of thetube assembly adjacent the target insertion point; and causing thedriver to apply the ejection force to the fastener, thereby ejecting thefastener through the distal opening and into the body tissue at thetarget insertion point.
 26. The method of claim 25, wherein the ejectionforce is applied to the barbed fastener by the driver as the driver ismoved distally from a pre-firing driver position to a distal-most driverposition adjacent the distal tube opening.
 27. The method of claim 26wherein a biasing force is applied to the driver by a spring when saiddriver is in the pre-firing driver position, said biasing force servingto bias the driver toward the distal-most driver position.
 28. Themethod of claim 25, wherein the applicator includes an actuationassembly having a trigger configured for rotational movement between aninitial trigger position, a pre-firing trigger position and apost-firing trigger position, the trigger and actuation assembly beingadapted so that movement of the trigger from the initial triggerposition to the pre-firing trigger position causes the indexer to movethe fastener from the initial position to the firing position, furthermovement of the trigger to the post-firing trigger position causes thedriver to apply the ejection force to the fastener, thereby ejecting thefastener through the distal opening and into the body tissue at thetarget insertion point.